Millimeter-wave communication station and methods for station and information discovery in a millimeter-wave basic service set

ABSTRACT

Embodiments of a millimeter-wave communication station and methods for station and information discovery in a millimeter-wave (mmW) basic-service set (BSS) are generally described herein. In some embodiments, a station-capability information element (IE) may be transmitted to a central coordinator of the BSS during association to provide station-capability information to the central coordinator. An information-request action frame may be transmitted to either discover or request information about the one or more other mmW stations. An information-response action frame may be from the target station that includes the requested information. Accordingly, mmW devices of the BSS may be able to discover each other and exchange station-capability information so that devices can communicate directly. A simplified and unified frame-format scheme for both station and information discovery suitable for use in a mmW WPAN or in a mmW WLAN is thus provided.

TECHNICAL FIELD

Embodiments pertain to millimeter-wave communication networks. Someembodiments pertain to wireless personal area networks (WPANs) andwireless local area networks (WLANs) that use millimeter-wavefrequencies to communicate. Some embodiments relate to millimeter-wavenetworks operating in accordance with the wireless gigabit alliance(WiGig) specification and the IEEE 802.11ad specification for very-highthroughput in 60 GHz. Some embodiments relate to millimeter-wavenetworks that operate in accordance with IEEE 802.15.3 specification forhigh-rate WPANs.

BACKGROUND

The millimeter-wave band has the available spectrum and is capable ofproviding significantly higher-level throughputs than the microwavefrequency band. Due to significantly higher attenuation levels and thedirectional nature of millimeter-wave signals, millimeter-wave devices(i.e., stations) generally employ highly-directional antennas as well asbeamforming techniques for communicating. Some key usages of themillimeter-wave frequency band may include transmissions to a wirelessdisplay, wireless docking, sync & go, real-time video streaming, andhigh-definition television (HDTV) streaming, among others. To enablethese key usages, millimeter-wave devices may need to discover eachother and exchange capability and service information. This is moredifficult in a millimeter-wave network due to the need forhighly-directional antennas and beamforming techniques.

Thus, there are general needs for millimeter-wave stations and methodsfor station and information discovery in a millimeter-wave network. Whatis also needed is a simplified and unified frame-format scheme for bothstation and information discovery suitable for use in a millimeter-waveWPAN or in a millimeter-wave WLAN.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a millimeter-wave (mmW) basic-service set (BSS), inaccordance with some embodiments;

FIG. 2 illustrates communications between the central coordinator and anon-central coordinator station, in accordance with some embodiments;

FIG. 3 illustrates communications between two non-central coordinatorstations, in accordance with some embodiments;

FIG. 4 illustrates a station-capability information element (IE), inaccordance with some embodiments;

FIG. 5 illustrates an information-request action frame, in accordancewith some embodiments;

FIG. 6 illustrates an information-response action frame, in accordancewith some embodiments; and

FIG. 7 illustrates a functional block diagram of a millimeter-wavestation, in accordance with some embodiments.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1 illustrates a mmW BSS, in accordance with some embodiments. ThemmW BSS 100 includes a plurality of mmW stations 104 that maycommunicate using millimeter waves. One of the mmW stations 104, thecentral coordinator 102, may operate as central coordinator for the mmWBSS 100 to coordinate communications among the mmW stations 104 andcontrol access to the wireless medium.

In some embodiments, the central coordinator 102 may broadcast a beaconframe that indicates the length of a beacon interval during whichcommunications are to take place. The beacon frame may be received bythe other mmW stations 104, thereby allowing the other mmW stations 104to know when the next beacon interval will occur. The centralcoordinator 102 and the mmW stations 104 may utilize directionalantennas and may employ beamforming, beam steering or beam directingtechniques to communicate therebetween. These embodiments are describedin more detail below.

In accordance with some embodiments, a simplified and unifiedframe-format scheme for both station and information discovery isprovided. The frame-format scheme may be suitable for use in both a mmWWPAN and a mmW WLAN. As described in more detail below, through the useof a station-capability information element, an information-requestaction frame, and an information-response action frame, the mmW stations104 of the mmW BSS 100 may be able to discover each other and exchangestation-capability information so that non-central coordinator devices,such as mmW station 104A and mmW station 104B, can communicate directlyin a peer-to-peer (P2P) manner.

In some embodiments, the central coordinator 102 and the mmW stations104 are configured to operate as part of a personal BSS (PBSS). Thecentral coordinator 102 may be a PBSS control point (PCP) operating as acentral coordinator for the PBSS, and the PBSS may be configured tooperate in accordance with a Wireless Gigabit Alliance (WiGig or WGA)specification or an IEEE 802.11 specification such as the Task Group ad(IEEE 802.11ad) draft specification for multi-gigabit speed wirelesscommunications technology operating over an unlicensed 60 GHz frequencyband. The PBSS may be configured to operate in accordance with the WiGigMedia-Access Control (MAC) or Physical Layer (PHY) specifications,version 1.0 or later, although this is not a requirement. In some otherembodiments, the PBSS may be configured to operate in accordance with anIEEE 802.15.3 specification for high-rate WPANs, including the IEEE802.15.3 Task Group 3c (TG3c).

In some embodiments, the central coordinator 102 and the mmW stations104 comprise an infrastructure BSS (IBSS). The central coordinator 102may be an access point (AP) operating as a central coordinator for theIBSS. The IBSS may be configured to operate in accordance with the WiGigspecification or the IEEE 802.11ad specification referenced above.

The mmW stations 104 may include wireless display devices, laptop andportable computers, mobile communication devices (e.g., cell phones,smart phones or personal digital assistant (PDAs)), hard drives andother storage devices, digital audio players (e.g., MP3 players), webtablets, wireless headsets, pagers and instant messaging devices,digital cameras, televisions, medical devices (e.g., a heart ratemonitor, a blood pressure monitor, etc.), or other device that mayreceive and/or transmit information using millimeter waves.

Through the use of the frame-format scheme described herein, the mmWstations 104 may discover each other and exchange station-capabilityinformation, which may allow for P2P communications therebetween. Forexample, wireless docking and sync & go techniques for a laptop computermay be achieved. Furthermore, a laptop computer will be able todetermine that a wireless display device is indeed a display and not awireless hard drive, for example, which will allow for wireless use ofthe display by the laptop computer. A cell phone may be able to discoverand determine the capabilities of an MP3 player so that it cansynchronize music files with the MP3 player. The mmW stations 104associated with a laptop (which may be operating as the centralcoordinator 102) may be able to discover each other, learn each other'scapabilities, and subsequently establish wireless connectionstherebetween.

In a conventional WLAN or WiFi network configured in accordance withconventional IEEE 802.11 specifications, station and service discoveryare less important since WLAN devices use microwave frequencies (whichare less directional the mmW frequencies) and because WLAN devices aregenerally configured to communicate directly with an access point.

FIG. 2 illustrates communications between a central coordinator 102 anda non-central coordinator station 104A, in accordance with someembodiments. A non-central coordinator station, such as mmW station 104A(FIG. 1A), may be configured to transmit a station-capability IE 204 tothe central coordinator 102 during association 202 with the BSS 100(FIG. 1). The station-capability IE 204 may be configured to providestation-capability information to the central coordinator 102. Thenon-central coordinator station 104A may also be configured to transmitan information-request action frame 206 to a target station to eitherdiscover or request information about the one or more other mmW stations104 (FIG. 1) of the BSS 100. The target station may be either thecentral coordinator 102 (as illustrated in FIG. 2) or one of the othermmW stations (e.g., non-central coordinator station 104B (FIG. 1)). Thenon-central coordinator station 104A may receive an information-responseaction frame 208 from the target station (e.g., the central coordinator102) that includes the requested information.

In some embodiments, an unsolicited information-response action frame210 may be sent unsolicited (i.e., not in response to aninformation-request action frame 206) by one of the mmW stations 104,such as by the central coordinator 102, to provide updated informationto the mmW stations 104 of the BSS 100. In some of these embodiments,the unsolicited information-response action frame 210 may be transmittedby the central coordinator 102 to the associated mmW stations 104 uponassociation of a new mmW station 104 with the BSS 100 or upondisassociation of a mmW station 104 with the BSS 100. The unsolicitedinformation-response action frame 210 may include station-capabilityinformation of all currently associated mmW stations 104 and may includethe station-capability information of the central coordinator 102. Anunsolicited information-response action frame 210 may also be sent atany time by the central coordinator 102.

In these embodiments, the transmission of the unsolicitedinformation-response action frame 210 by the central coordinator 102 toall mmW stations 104 associated with BSS 100 allows currently associatedmmW stations 104 to maintain up-to-date information about the othercurrently associated mmW stations 104. An unsolicitedinformation-response action frame 210 may also be sent by a non-centralcoordinator station 104 to provide an information update directly to oneor more other non-central coordinator stations 104 in the BSS 100.

As described in more detail below, the station-capability informationprovided in the station-capability IE 204, requested and/or provided inthe information-request action frame 206, or provided in theinformation-response action frame 208 allows a mmW station 104 to knowthe capabilities of other mmW stations 104. The station-capabilityinformation may include one or more of beamforming capabilities, thenumber of antennas and antenna capabilities, the number of elements perantenna, supported modulations and modulation capabilities, supportedchannels, and multi-user (MU) multiple-input multiple-output (MIMO)capabilities, among other things. This exchange of information may allowany non-central coordinator station 104 to subsequently performbeamforming training for subsequent communication therebetween.

FIG. 3 illustrates communications between two non-central coordinatorstations, in accordance with some embodiments. An initiating non-centralcoordinator station 304A may transmit an information-request actionframe 306 to another non-central coordinator station 304B to eitherdiscover or request information about the other the other non-centralcoordinator station 304B. The other non-central coordinator station 304Bmay be configured to respond by transmitting an information-responseaction frame 308 that includes the requested information. In someembodiments, the initiating non-central coordinator station 304A maytransmit the information-request action frame 306 to the othernon-central coordinator station 304B after the initiating non-centralcoordinator station 304A has received station-capability informationabout the other non-central coordinator station 304B from the centralcoordinator 102 (FIG. 1), although this is not a requirement.

The initiating non-central coordinator station 304A may correspond tonon-central coordinator station 104A (FIG. 1) and the other non-centralcoordinator station 304B may correspond to non-central coordinatorstation 104B (FIG. 1).

FIG. 4 illustrates a station-capability IE, in accordance with someembodiments. Station-capability IE 400 may be suitable for use asstation-capability IE 204 (FIG. 2) and may be transmitted from one mmWstation 104 (FIG. 1) to another mmW station 104 to providestation-capability information to the other mmW station 104. In someembodiments, the station-capability IE 400 may be transmitted by a mmWstation 104 to the central coordinator 102 (FIG. 1) during association202 (FIG. 2) with the BSS 100 (FIG. 1) to provide station-capabilityinformation to the central coordinator 102.

In some embodiments, one or more station-capability IE 400 may beincluded as part of the information-request action frame 206 (FIG. 2) orthe information-request action frame 306 (FIG. 3) to providestation-capability information within the frame. One or morestation-capability IE 400 may also be included as part of theinformation-response action frame 208 (FIG. 2) or theinformation-response action frame 308 (FIG. 3) to providestation-capability information within the frame.

In accordance with some embodiments, the station-capability IE 400 mayinclude a station (STA) address 402 of the sending mmW station (e.g.,mmW station 104A (FIG. 1)), an association identifier (AID) 404 of thesending mmW station, and station-capability information 406 of thesending mmW station. The station address 402 may be a MAC address of thesending mmW station, and the association ID 404 may have been assignedby the central coordinator 102 during association 202. Thestation-capability information 406 may include station-capabilityinformation of the sending mmW station and may include at least somebasic capabilities of the sending mmW station. As discussed in moredetail below, the information included in the station-capability IE 400may be distributed by the central coordinator 102 in aninformation-response action frame 208 (FIG. 2) when requested or in anunsolicited information-response action frame 210 (FIG. 2).

FIG. 5 illustrates an information-request action frame 500, inaccordance with some embodiments. Information-request action frame 500may be suitable for use as information-request action frame 206 (FIG. 2)and information-request action frame 306 (FIG. 3). In some embodiments,a sending mmW station, such as non-central coordinator station 104A(FIG. 1), may transmit the information-request action frame 500 to atarget station to either discover or request information about the oneor more other mmW stations 104 (FIG. 1) in the BSS 100 (FIG. 1). Thetarget station may be either the central coordinator 102 (FIG. 1) or oneof the other mmW stations (e.g., non-central coordinator station 104B).

In some embodiments, the information-request action frame 500 may alsoinclude station-capability information of the sending mmW station. Thesending mmW station may also configure the information-request actionframe 500 to include station-capability information of other mmWstations 104 that are known to the sending mmW station, in addition tothe station-capability information of the sending mmW station. Theinformation-request action frame 500 may allow the sending mmW stationto either discover other mmW stations 104 or request information aboutthe one or more other mmW stations 104 of the BSS 100.

In some embodiments, the information-request action frame 500 includesat least a target address field 503 and a request IE field 504. Thetarget address field 503 may include an address of the target station,and the request IE field 504 may be configured to indicate the types ofinformation elements that the sending mmW station is requesting from thetarget station (e.g., either the central coordinator 102 or anon-central coordinator station such as mmW station 104B).

When the information-request action frame 500 is transmitted to thecentral coordinator 102 (as illustrated in FIG. 2) and when the targetaddress field 503 includes a broadcast address, the sending mmW stationmay be requesting information about all the other mmW stations 104 thatare associated with the central coordinator 102. The request IE field504 may allow the sending mmW station to specify which types of IEs arebeing requested from the target station. In some embodiments, almost anytype of IE may be requested in the request IE field 504.

As further illustrated in FIG. 5, the information-request action frame500 may also include a category field 501 to indicate that theinformation-request action frame 500 is a frame applicable to a mmW BSS,and an action field 502 to indicate that information-request actionframe 500 is requesting information. In some embodiments, category field501, action field 502, and request IE field 504 may be configured inaccordance with section 7.3.2.12 of the IEEE 802.11 ad specification,although this is not a requirement.

When the information-request action frame 500 is transmitted to anothernon-central coordinator station, such as non-central coordinator station304B (as illustrated in FIG. 3), the target address field 503 mayinclude a MAC address of the other non-central coordinator station 104Bindicating that the sending mmW station is requesting information aboutthe other non-central coordinator station 104B directly from the othernon-central coordinator station 104B. Accordingly, peer non-centralcoordinator stations may discover each other and request informationabout each other. Furthermore, this exchange of information may allowdirect-link setup (DLS) performed between peer non-central coordinatorstations.

Accordingly, an information-request action frame 500 may be used by ammW station 104 to request information about either a single station inthe BSS 100 or about all of the associated mmW stations 104 in the BSS100. If a mmW station 104 is requesting information about only a singlemmW station 104 in the BSS 100 (FIG. 1), the requesting station may setthe target address field 503 in the frame to the MAC address of thatsingle mmW station 104. If a mmW station 104 is requesting informationabout all of the mmW stations 104 in the BSS 100, it may set the targetaddress field 503 in the frame to the broadcast address and may transmitthe information-request action frame 500 to the central coordinator 102.

In some embodiments, the information-request action frame 500 may alsoinclude a station-capability field 505 that includes station-capabilityinformation about the sending mmW station (i.e., the source station) andstation-capability information about other mmW stations 104 that areknown to the sending mmW station. The information-request action frame500 may also include an optional IE-provided field 506 that includes anactual IE that the sending mmW station is providing to the targetstation. In these embodiments, an information-request action frame 500may provide the capabilities and any other IEs of the sending mmWstation (i.e., the source station). This reduces the number ofhandshakes between the two mmW stations 104.

As illustrated in FIG. 5, a station-capability field 505 may be includedin the information-request action frame 500 for each mmW station forwhich station-capability information is being provided. As alsoillustrated in FIG. 5, an IE-provided field 506 may also be provided foreach IE that is provided. As also illustrated in FIG. 5, one or morevendor-specific IE 507 may also be included in the information-requestaction frame 500. Accordingly, a simplified and unified frame-formatscheme for both station and information discovery suitable for use in ammW WPAN or a mmW WLAN is provided.

FIG. 6 illustrates an information-response action frame 600, inaccordance with some embodiments. The information-response action frame600 may be suitable for use as information-response action frame 208(FIG. 2) or information-response action frame 308 (FIG. 3). Theinformation-response action frame 600 may transmitted by a mmW stationeither unsolicited or in response to receipt of the information-requestaction frame 500 (FIG. 5). When the information-response action frame600 is sent in response to an information-request action frame 500, itmay be referred to as a solicited information-response action framebecause it was requested by another mmW station. When theinformation-response action frame 600 is not sent in response to aninformation-request action frame 500, it may be referred to as anunsolicited information-response action frame 210 (FIG. 2).

In accordance with the embodiments illustrated in FIG. 6, theinformation-response action frame 600 may include a target address field603 and a request IE field 604. The target address field 603 may includean address of a target station (i.e., that station that is to receivethe information-response action frame 600) when the information-responseaction frame 600 is solicited. The target address field 603 may includea broadcast address when the information-response action frame 600 isunsolicited.

The request IE field 604 may be configured to indicate the types ofinformation elements that are being provided in the information-responseaction frame 600. The information-response action frame 600 may alsoinclude one or more optional station capability fields 605 to indicatestation capability of one or more mmW stations 104. Theinformation-response action frame 600 may also include one or moreoptional IE-provided fields 606 to include the actual informationelements that the mmW station 104 transmitting the information-responseaction frame 600 is providing to the mmW station 104 receiving theinformation-response action frame 600. As also illustrated in FIG. 6,the information-response action frame 600 may also include a categoryfield 601, an action field 602, and one or more vendor-specific fields607, similar to fields 501, 502 and 507, respectively, as discussedabove.

FIG. 7 illustrates a functional block diagram of a mmW station 700, inaccordance with some embodiments. The mmW station 700 may be suitablefor use as any one of mmW stations 104 (FIG. 1), including the centralcoordinator 102 (FIG. 1). The mmW station 700 may include one or moreantennas 701 that may be configured for communicating millimeter wavesignals either in a directional manner or in a non-directional manner.In accordance with embodiments, the mmW station 700 may configure theantennas 701 for non-directional communications for establishing aninitial contact with another mmW station, and may configure the antennas701 for directional communications after establishing an initial contactwith the other mmW station. In these embodiments, station-capabilityinformation received from the other station or received from the centralcoordinator 102 may be used for the directional communications. In someembodiments, beam-forming training may be performed and beamformingcoefficients may be employed for the directional communications.

The mmW station 700 may include mmW PHY layer 702, MAC layer 704, andmemory 706. In some embodiments, the mmW station 700 may implement themmW PHY layer 702 and the MAC layer 704 in accordance with a WiGig PHYand MAC specifications (or the IEEE 802.11ad specification) formulti-gigabit speed wireless communications technology operating overthe unlicensed 60 GHz frequency band. Memory 706 may be configured tostore, among other things, the station-capability information receivedfrom other mmW stations for use in communicating with the other mmWstations.

Although mmW station 700 is illustrated as having several separatefunctional elements, one or more of the functional elements may becombined and may be implemented by combinations of software-configuredelements, such as processing elements including digital signalprocessors (DSPs) and/or other hardware elements. For example, someelements may comprise one or more microprocessors, DSPs, applicationspecific integrated circuits (ASICs), radio-frequency integratedcircuits (RFICs) and combinations of various hardware and logiccircuitry for performing at least the functions described herein. Insome embodiments, the functional elements of mmW station 700 may referto one or more processes operating on one or more processing elements.

Antennas 701 may comprise one or more directional or omnidirectionalantennas, including, for example, dipole antennas, monopole antennas,patch antennas, loop antennas, microstrip antennas or other types ofantennas suitable for transmission of RF signals. In some embodiments,instead of two or more antennas, a single antenna with multipleapertures may be used. In these embodiments, each aperture may beconsidered a separate antenna. In some MIMO embodiments, antennas 701may be effectively separated to take advantage of spatial diversity andthe different channel characteristics that may result between each ofantennas 701 and the antennas of a sending mmW station. In some MIMOembodiments, antennas 701 may be separated by up to 1/10 of a wavelengthor more.

In some embodiments, the mmW station 700 may be configured to performassociation beamforming training (A-BFT) with collision avoidance, inaccordance with U.S. patent application Ser. No. 12/559,770, filed Sep.15, 2009, [docket no. 884.191US1] entitled “MILLIMETER-WAVECOMMUNICATION STATION AND METHOD FOR SCHEDULING ASSOCIATION BEAMFORMINGTRAINING WITH COLLISION AVOIDANCE.” In some embodiments, the mmW station700 may be configured to perform multiple-access beamforming andbeamforming training in accordance with U.S. patent application Ser. No.12/574,140, filed Oct. 6, 2009 [docket no. 884.1941551] entitled“MILLIMETER-WAVE COMMUNICATION STATION AND METHOD FOR MULTIPLE-ACCESSBEAMFORMING IN A MILLIMETER-WAVE COMMUNICATION NETWORK.”

Referring to FIGS. 1-6, in accordance with some embodiments, the mmWstations 104 and the central coordinator 102 may implement a set ofprotocol procedures. For example, a sending mmW station 104 may transmitan information-request action frame 500 to a destination station 104 inthe BSS 100 with a length field of the request IE 504 set to zero todetermine if the destination mmW station is still present in the BSS 100and is within range of the sending mmW station 104.

A sending mmW station 104, such as non-central coordinator station 104A,may transmit an information-request action frame 500 that includes itsstation-capability information element 400 and other informationelements. However, a sending mmW station 104, such as non-centralcoordinator station 104A, may be prohibited from including thestation-capability information of another station within aninformation-request action frame 500.

As discussed above, a sending mmW station 104 may transmit aninformation-response action frame 600 either as a response to aninformation-request action frame 500, or it may be sent unsolicited. Ifthe sending mmW station 104 is providing information about a singleother mmW station of the BSS 100, the sending mmW station 104 may setthe target address field 603 in information-response action frame 600 toa MAC address of that single other mmW station. If a sending mmW station104 is providing information about all of the stations in the BSS 100 inthe information-response action frame 600, it may set the target addressfield 603 in information-response action frame 600 to the broadcastaddress.

In accordance with some embodiments, a responding station 104 (either astation 104 or the central coordinator 102) may be configured toinclude, in an information-response action frame 600, the informationelements that were requested by the station requesting the information.A responding station (either a station 104 or the central coordinator102) may also be configured to send an information-response action frame600 with an empty payload in response to a received information-requestaction frame 500 for which the requesting mmW station solicitsinformation about a single station that is not a member of the BSS 100and the responding station is the central coordinator 102 (or that isnot the responding station itself). Otherwise, the responding stationmay send an information-response action frame 600 with the informationrequested by the requesting station.

Embodiments may be implemented in one or a combination of hardware,firmware and software. Embodiments may also be implemented asinstructions stored on a computer-readable storage device, which may beread and executed by at least one processor to perform the operationsdescribed herein. A computer-readable storage device may include anynon-transitory mechanism for storing information in a form readable by amachine (e.g., a computer). For example, a computer-readable storagedevice may include read-only memory (ROM), random-access memory (RAM),magnetic disk storage media, optical storage media, flash-memorydevices, and other storage devices and media. In some embodiments,system 100 may include one or more processors and may be configured withinstructions stored on a computer-readable storage device.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

1. A millimeter-wave (mmW) station configured to: transmit astation-capability information element to a central coordinator duringassociation to provide station-capability information to the centralcoordinator; transmit an information-request action frame to a targetstation to request information about one or more other mmW stations of abasic-service set (BSS), the target station being either the centralcoordinator or one of the other mmW stations; and receive aninformation-response action frame from the target station that includesthe requested information.
 2. The mmW station of claim 1, wherein thecentral coordinator and the mmW stations are configured to operate aspart of a personal BSS (PBSS), wherein the central coordinator is a PBSScontrol point (PCP) operating as a central coordinator for the PBSS; andwherein the PBSS is configured to operate in accordance with a WirelessGigabit Alliance (WiGig) specification or an IEEE 802.11 specificationfor multi-gigabit speed wireless communications technology operatingover an unlicensed 60 GHz frequency band.
 3. The mmW station of claim 1,wherein the central coordinator and the mmW stations comprise aninfrastructure BSS (IBSS), wherein the central coordinator is an accesspoint (AP) operating as a central coordinator for the IBSS; and whereinthe IBSS is configured to operate in accordance with a Wireless GigabitAlliance (WiGig) specification or an IEEE 802.11 specification formulti-gigabit speed wireless communications technology operating over anunlicensed 60 GHz frequency band.
 4. The mmW station of claim 1, whereinthe mmW station is a sending mmW station; and wherein the sending mmWstation configures the information-request action frame to furtherinclude station-capability information of the sending mmW station. 5.The mmW station of claim 4, wherein the station-capability informationelement includes a station address of the sending mmW station, anassociation identifier (ID) of the sending mmW station andstation-capability information of the mmW sending mmW station.
 6. ThemmW station of claim 5, wherein the information-request action frameincludes at least a target address field and a requestinformation-element (IE) field, wherein the target address fieldincludes an address of the target station; and wherein the request IEfield is configured to indicate types of information elements that thesending mmW station is requesting from the target station.
 7. The mmWstation of claim 6, wherein when the information-request action frame istransmitted to the central coordinator and when the target address fieldincludes a broadcast address, the sending mmW station is requestinginformation about the other mmW stations that are associated with thecentral coordinator.
 8. The mmW station of claim 6, wherein when theinformation-request action frame is transmitted to a non-centralcoordinator station of the BSS, the target address field is configuredto include a media-access control (MAC) address of the non-centralcoordinator station indicating that the sending mmW station isrequesting information about the non-central coordinator stationdirectly from the non-central coordinator station.
 9. The mmW station ofclaim 6, wherein when the information-request action frame furtherincludes: a station-capability field that includes station-capabilityinformation about the sending mmW station and station-capabilityinformation about other mmW stations of the BSS that are known to thesending mmW station; and an IE-provided field that includes an IE thatthe sending mmW station is providing to the target station.
 10. The mmWstation of claim 4, wherein the information-response action frame istransmitted by the target station in response to receipt of theinformation-request action frame.
 11. The mmW station of claim 4,wherein an unsolicited information-response action frame is sent by oneof the mmW stations to provide updated information to the other mmWstations, wherein the unsolicited information-response action frame istransmitted by the central coordinator to associated mmW stations of theBSS upon association of a new mmW station with the BSS or upondisassociation of a mmW station with the BSS; and wherein theunsolicited information-response action frame includesstation-capability information of currently associated mmW stations andthe central coordinator.
 12. The mmW station of claim 4, wherein theinformation-response action frame includes at least a target addressfield and a request information-element (IE) field, wherein the targetaddress field includes an address of a target station; and wherein therequest IE field is configured to indicate types of information elementsthat are being provided by the mmW station that is transmitting theinformation-response action frame.
 13. The mmW station of claim 12,wherein the information-response action frame further includes: one ormore station capability fields to indicate station capability of one ormore stations; and one or more optional IE-provided fields to includeinformation elements that the target station is providing to the mmWstation that is receiving the information-response action frame.
 14. Amethod for station discovery and information exchange in amillimeter-wave (mmW) basic-service set (BSS), the method comprising:transmitting a station-capability information element to a centralcoordinator during association to provide station-capability informationto the central coordinator; and receiving either a solicited or anunsolicited information-response action frame that includesstation-capability information of one or more mmW stations of the BSS,wherein the station-capability information is for use by two of the mmWstations of the BSS to perform beamforming training for subsequentcommunications therebetween.
 15. The method of claim 14 furthercomprising: transmitting an information-request action frame to a targetstation of the BSS to either discover or request information about theone or more mmW stations of the BSS, wherein the target station iseither the central coordinator or a non-central coordinator station; andwherein the solicited information-response action frame is received fromthe target station in response to the information-request action frame.16. The method of claim 15 further comprising configuring theinformation-request action frame to include: a target address field thatincludes an address of the target station; and a requestinformation-element (IE) field that is configured to indicate types ofinformation elements that a sending mmW station is requesting from thetarget station, wherein when the target address field of theinformation-request action frame includes a broadcast address, thesending mmW station is requesting information about other mmW stationsof the BSS; and wherein when the target address field includes anaddress of a non-central coordinator station of the BSS, the sending mmWstation is requesting information about the non-central coordinatorstation directly from the non-central coordinator station.
 17. Themethod of claim 16 further comprising configuring theinformation-request action frame to further include: astation-capability field that includes station-capability informationabout the sending mmW station and station-capability information aboutother mmW stations that are known to the sending mmW station; and anIE-provided field that includes an information element that the sendingmmW station is providing to the target station.
 18. A millimeter-wave(mmW) station configured to operate as a central coordinator of abasic-service set (BSS) that includes one or more associated mmWstations, the central coordinator configured to: receive astation-capability information element (IE) from each of the mmWstations during association with the BSS; and transmit an unsolicitedinformation-response action frame to the associated mmW stations uponassociation of another mmW station with the BSS or upon disassociationof a mmW station with the BSS, wherein the unsolicitedinformation-response action frame includes station-capabilityinformation of currently associated mmW stations and station-capabilityinformation of the central coordinator.
 19. The mmW station of claim 18,wherein the central coordinator is further configured to receiveinformation-request action frames from currently associated mmW stationsthat are requesting information about one or more other currentlyassociated mmW stations; and transmit solicited information-responseaction frames that include requested information to requesting mmWstations in response to the information-request action frames, whereinthe unsolicited and the solicited information-response action framesinclude station-capability information to allow non-central coordinatorstations of the BSS to perform beamforming training together forsubsequent communications therebetween.
 20. The mmW station of claim 19,wherein when a target address field of the information-request actionframe received from a requesting mmW station includes a broadcastaddress, the requesting mmW station is requesting information about oneor more other currently associated mmW stations, and wherein the centralcoordinator configures the information-response action frame to include:one or more station capability fields to indicate station-capabilityinformation of one or more mmW stations associated with the BSS; and oneor more optional IE-provided fields to include information elements ofthe one or more other currently associated mmW stations.